Save our Stages Act or the SOS Act This bill authorizes the Small Business Administration (SBA) to make grants to eligible live venue operators, producers, promoters, or talent representatives to address the economic effects of the COVID-19 (i.e., coronavirus disease 2019) pandemic on certain live venues. Specifically, the SBA may make (1) an initial grant of up to $12 million dollars to an eligible operator, promoter, producer, or talent representative; and (2) a supplemental grant that is equal to 50% of the initial grant. An initial grant must be used for costs incurred between March 1, 2020, and December 31, 2020, but a supplemental grant may be used for expenses incurred through June 30, 2021. Such grants shall be used for specified expenses such as payroll costs, rent, utilities, and personal protective equipment.